While the slide in prices into a bear market increases the chances of a reduction, trimming output by more than 500,000 barrels a day would mean further cuts are needed starting 2016 as higher prices prompt more U.S. drilling, Goldman said in a note. Some members of the Organization of Petroleum Exporting Countries including Saudi Arabia have resisted calls to decrease supply while others seek action to support crude.

“A large cut would be difficult to implement,” given the financing needs of some OPEC members, said analysts including New York-based Jeffrey Currie, referring to Libya, Iran, Venezuela and Iraq, the group’s second-largest member.

Oil has slumped about 30 percent since its June peak amid a surge in U.S. output to the highest level in more than three decades. OPEC, which meets Nov. 27 in Vienna, exceeded its 30 million barrel a day production target for a fifth consecutive month in October, according to data compiled by Bloomberg.

Brent crude, the benchmark for more than half of the world’s oil slid as much as 46 cents to $78.85 a barrel on the London-based ICE Futures Europe exchange.

OPEC Meetings

OPEC members have stepped up diplomacy before the meeting. Iranian oil minister Bijan Namdar Zanganeh is preparing to visit the United Arab Emirates, while Iraqi President Fouad Masoum and Libyan Prime Minister Abdullah al-Thani flew to Riyadh last week for separate talks with officials from Saudi Arabia, the group’s biggest producer.

Rafael Ramirez, Venezuela’s foreign minister and representative to OPEC, held talks in Algeria and Qatar while Saudi Oil Minister Ali Al-Naimi toured Latin America. The group last cut quotas in December 2008, trimming its target by 2.46 million barrels a day in response to the global financial crash. It produced 30.97 million barrels daily last month, data compiled by Bloomberg show.

Some OPEC members have cut prices of supplies to defend market share and stimulate demand amid the shale boom in North America. U.S. daily crude output climbed to 9.06 million barrels in the week ended Nov. 7, the most in weekly Energy Information Administration data that began in 1983.

Iraq, which pumped 3.3 million barrels a day last month, will be reluctant to enact production cuts, given the ongoing domestic instability, military funding needs and Kurdistan’s desire and ability to increase exports, according to Goldman Sachs.

The Kurdistan Regional Government on Nov. 13 announced an agreement on exports with Iraq, in which the semi-autonomous region’s oil will be exchanged for revenues from the administration in Baghdad. The KRG has placed 150,000 barrels a day of crude at the disposal of the central government, according to a statement last week.